Cross-Pollination of Mandarins redux

Discussion in 'Citrus' started by Junglekeeper, Nov 6, 2005.

  1. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    For varieties that are often listed as requiring cross-pollination, wouldn't it be more accurate to say "cross-pollination required to produce higher yields"?

    What sort of yield can be expected for a tree that isn't cross-pollinated? Yield will of course depend on the variety but in what magnitude? (e.g. a dozen vs. dozens?) For the non-commercial grower, would this lower yield still be enough to satisify the average grower and with the added benefit of fruits containing fewer seeds?
     
  2. AnotherAlterEgo

    AnotherAlterEgo Active Member

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    Re: Cross-Pollination of Mandarins

    Junglekeeper - I'm not sure I'm answering your question here, but some mandarins (such as the Satsuma) set fruit without pollination, which is defined as autonomic parthenocarpy. In at least two commercial groves that I am aware of, Tangelos are planted intermittently for the purpose that you described. Once again, I'm not sure that I have answered your question, but I hope I've brought you closer to an answer, at least. Take care.
     
  3. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Re: Cross-Pollination of Mandarins

    I'm only wondering about varieties in which cross-pollination would be helpful. For example. What would happen if you plant a Minneloa tangelo without a pollinator?
     
  4. AnotherAlterEgo

    AnotherAlterEgo Active Member

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    Re: Cross-Pollination of Mandarins

    Junglekeeper - Keep in mind that my professional experience involves container trees. I can tell you that most citrus is self-fertile, meaning they don't require cross pollination. On the other hand, Tangelos are planted in some groves to increase fruit set. So, in the opinions of some who make their livings producing citrus fruit, cross-pollination is good. But, as far as increasing the yield on Tangelos, I'm not rightly sure. Are there any commercial producers out there? (Sorry, my knowledge in this area is quite limited.)
     
  5. Millet

    Millet Well-Known Member 10 Years

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    Re: Cross-Pollination of Mandarins

    Junglekeeper, to quickly answer your question...if you planted a Minneloa Tangelo with a pollinator so that cross pollination could occur, then the fruit crop produced by the Minneola Tangelo would GREATLY increase. The variety Mineola Tangelo is called "self imcompatible. Self incompatible means that the pollen is incompatible with the postils, even though the ovules of the flower are fertile. In other words the pollen is incapable of bringing about sexual fertilization even though both male and female components are functional. Incompatibility in citrus is due to slow pollen tube growth, apparently caused by inhibitors in the style. This results in abscission of the style BEFORE the pollen tube can enter the ovary and discharge it's sperm nucei into the embryo sac. Sexual fertilization is thereby precluded and fruit set of non-parthenocarpic varieties is nil to very little. Both Sunburst Mandarin and Temple are excellent polinators for Minneola Tangelos, and when cross pollination occurs your Minneola will produce a very good crop. However,also keep in miind that Minneola Tangelos are notorious for alternate bearing. If you do not have a Sunburst or a Temple, you can "pollinate" the Minneola blooms with Gibberellic Acid. GA sprays at 10ppm concentration applied from full bloom to two-thirds petal fall have effectively set and produced commercial size crops on Orlando and Minneolas. Fruits induced by GA are reduced in size and development of orange peel color is slightly delayed. BTW, if you want to try something fun to pollinate self-incompatible tangelos try this. When flowers are opened by hand well before the flower would normally open and self-pollinated by hand their self-incompatibility is many times ove come. It is not really known whether this was due to the very short style (thus shorter pollin tube growth), or to the absence of chemical inhibition in the style. Lastly Minneola are WEAKLY parthenocarpic so lack of sexual fertilizaton can result in some fruit, though usually nil. Hope I have helped to answer your needs. Take care, and good luck. - MIllet
     
  6. AnotherAlterEgo

    AnotherAlterEgo Active Member

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    Re: Cross-Pollination of Mandarins

    Millet - That information is fascinating. I'm saving it for the archives. Thank you for your research on the matter. Question: Is giberrelic acid useful in increasing yield on trees in the autonomic parthenocarpy category?
     
  7. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Re: Cross-Pollination of Mandarins

    Thanks for your informative reply, Millet. It may come in handy. It's always interesting to know the reasons why plants behave the way they do. To recap, the answer would be 'yes' and the expected yield of an unpollinated tree would depend on its degree of parthenocarpy?

    My question didn't start off being about one of my trees but now I suspect one of the seed-grown plants is a Minneola based on my history of consumption and the help of Malcolm Manners' image collection of citrus leaves. The other seed-grown plant is likely a mandarin or mandarin-hybrid. Maybe these two trees will cross-pollinate each other one day.
     
  8. mr.shep

    mr.shep Well-Known Member 10 Years

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    Re: Cross-Pollination of Mandarins

    In regards to a Minneola Tangelo the trees
    can still be cross pollinated by another
    Minneola Tangelo. The tree is incapable
    of being selfed. So, in Junglekeeper's
    case most any nearby Citrus can act as
    a pollinizer for his Minneola Tangelo.
    For a while there was thought that indoor
    Kaffir Limes needed a pollinizer so some
    people bought two trees instead of one
    so they could pollinize each other. The
    Lime may be capable of producing one
    or two Limes on its own but if we have
    a second Lime we may get 8-10 Limes
    on each tree. The problem here is that
    the fruit has little use at this time. Most
    people have the Limes for the leaves for
    cooking and for teas. Even the leaves by
    themselves are not very fragrant until
    we crack or crush them and then their
    aromatic perfumes will be liberated.

    Jim
     
    Last edited by a moderator: Nov 8, 2005
  9. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Even though it's often acknowledged that citrus can freely hybridize, wouldn't the chances or rate of pollination be greatly increased by related varieties, in this case a grapefruit, mandarin or mandarin hybrid?

    Also, does Minneola grow true-to-type from seed?

    I'm really looking forward to seeing this tree (whatever it is) flower which probably won't be for another couple of years. Interestingly it's the biggest, most robust citrus that I have - just have to respect its 1.5" thorns!

    - So Kaffir lime is also weakly parthenocarpic?
    - In general, would a clone (rooted cutting) qualify as a pollinizer for its mother plant?
     
  10. Laaz

    Laaz Active Member 10 Years

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  11. mr.shep

    mr.shep Well-Known Member 10 Years

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    Obviously I may have made a mistake and I'll
    hone up to it. I should have written that the
    Minneola is incapable of being selfed without
    some help. With the advent of bees, a Minneola
    by itself can produce some fruit but I've also seen
    a neighbor's patio tree I bought for him that did
    not produce any fruit for 4 years until we moved
    it next to a few of my Citrus (in between a planted
    Trovita Orange and a planted Sampson Tangelo)
    and then the Minneola went from a zero to having
    a fruit set count of 31 that year.

    If we look at the links that we have to work with,
    what is wrong with this picture below? Could there
    be two forms of Minneola Tangelo?

    'Minneola'-a hybrid of 'Bowen' grapefruit and 'Dancy'
    tangerine.*1

    *1 Tangelo (Citrus paradisi × Citrus reticulata)

    The Minneola tangelo is a Duncan grapefruit x Dancy
    tangerine hybrid released in 1931 by the United States
    Department of Agriculture Horticultural Research Station
    in Orlando.*2

    *2 Minneola Tangelo

    Junglekeeper, I believe that I wrote a while back that
    a Kaffir Lime would do better having a second Lime
    around. This is also true for the Minneola Tangelo.
    A second tree with some bee activity should yield
    some fruit set.

    I am not going to go down the list for which pollinizer
    is better to use for a Minneola as most of the plantings
    near where I am use no pollinizers for the Minneola
    but do use plenty of beehives in a production grove
    setting.

    As to the question as to whether a Minneola will come
    true from seed, let me put it this way. We are already
    dealing with a hybrid fruit grafted onto let's say Trifoliate
    Orange rootstock. What is the likelihood that the fruit
    yielded from seed gathered from the fruit will be true
    to its parent? What factors are working against us for
    the fruit to be just like the parent? What factors are
    working for us if the Minneola came from a rooted
    cutting instead?

    Here is an example of a plant I have in my yard. I
    brought in a Florida Honey Mandarin that was grafted
    onto Trifoliate Orange rootstock. I planted the seeds
    from the fruit from the Honey Mandarin and have a
    tree that looks just like a Trifoliate Orange that produces
    fruit the same size, shape and color of a Honey Mandarin,
    yet the fruit is seedless and is sour.

    Here is another example I also have in my yard. I let
    some seed germinate off our cutting grown Meyer
    Lemon. The offspring look the same as the parent
    for color, leaf size and shape and have fruit that appears
    like and tastes like its parent.

    Now the question is, which would you prefer to have
    to grow on as seed, a fruit from the Honey Mandarin
    or a fruit from the Meyer Lemon? Now ask me if
    the grafted Minneola will be true to type. The result
    is that the fruit from the Minneola may resemble
    a Tangelo in color and the growth habit of the tree,
    this is not out of bounds, but will the fruit from the
    seedling bear fruit consistent in quality to the parent?
    Guaranteed true to type means the fruit from the
    seedlings will be a Tangelo but will the seeds be
    guaranteed to be a Minneola? We can guarantee
    that the seedlings raised from a cutting grown parent
    will be closer to being like its parent than the seed
    from the grafted parent will be.

    Yes, a rooted cutting offspring from a Kaffir Lime parent
    can help be a pollinizer for the parent.

    Jim
     
  12. Millet

    Millet Well-Known Member 10 Years

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    Jim, may I differ with you concerning Minneola being compatible with another Minneola? I guess it depends on your definition. Minneola is unable to pollenize another Minneola tree, by all acceptable "commerical" definitions of compatibility. Meaning that self, or cross pollination by another Minneola will not result in a profitable citrus crop. Therefore, when Minneola's are grown in a grove, pollenizer trees are always interplanted within the grove in order to get a crop. Usually, Sunburst, Fallglo, and especially Temple. If one wants to get VERY percise, than yes, Minneola would be a "pollinator" to another Minneola tree, but a VERY POOR pollinator, and would not produce an acceptable crop. Citrus growers would never grow a block of pure Minneolas, it would be a disaster economicly. So for Junglekeeper, if she cross pollinated two Minneolas, the resulting crop would be nil when compared to a crop produced by cross pollination with Temple, Sunburst, Fallglo or even GA3. No sweet orange or grapefriut variety is considered a "SATISFACTORY" pollenizer, even through some seedy varieties of oranges are slightly effective. I would count Orlando, Robinson, Page and Murcott as completely non pollenizers. Jim your return comments on my views, as stated in this thread, are ALWAYS welcome and valuable. BTW I intend to answer your e-mail to me. I have recently had little time due to various business meetings. Take care. - Millet
     
  13. Millet

    Millet Well-Known Member 10 Years

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    Jim ,I evidently wrote my thread at the same time you wrote your last response. Therefore, some of my concerns has been answered. Concerning Junglekeepers question, I would say that a Minneola seed produced by self pollinization or "pollinated" by another Minneola would be true from seed because Minneola's being very weakly parhenocarpic it would probably be a nucelar seed. - Millet
     
  14. mr.shep

    mr.shep Well-Known Member 10 Years

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    Millet, I understand but how we work things out
    here can be different than Florida. We did not
    use Temple Tangor much here as a pollinizer
    for a Minneola in the old plantings as the Tangor
    was not available then for commercial plantings,
    neither were the Fallglo and the Sunburst which
    really is rather recent as pollinizers for commercial
    purposes. So, how did we do it and succeed
    growing Minneola Tangelo without using a
    pollinizer?

    Some people want lots of Minneolas that have to
    be thinned. We'd rather have fewer fruit that get
    larger in size as the export market for here is for
    larger sized fruit. We can go without thinning
    the trees as often as other parts of the country as
    our market is slightly different than theirs is. If
    you look at the University of Florida at Gainesville
    link you will read that they consider the Minneola
    Tangelo to be "Minneola is not strongly self-fruitful"
    which gives rise to the fact that they did not write
    that the Minneola is not self fruitful at all. Obviously
    there are some conditions that exist that makes them
    feel that the Minneola can be somewhat self-fruitful
    but not strongly or better put not a reliable producer
    of its own accord. Where it is written that Minneola
    cannot cross pollinate another Minneola and under
    what conditions can a Minneola serve as a pollen
    source for another Minneola?

    We also cannot compare a patio tree or a dwarfed
    form to be equal to a commercial standard either
    in how they will set fruit. Container grown Minneola
    can differ greatly than a planted Minneola will, which
    is not always pointed out. Then there is the notion
    that there are or may be two forms of Minneola and
    one form is better for selfing with some help than the
    other form is. Let me say this now that the original
    Minneolas planted in commercial groves here are
    not the same plant that we see sold in nurseries
    for the homeowners and collectors and may not be
    the same plant as the ones being planted in Florida
    that may require a pollinizer to help them along.

    Jim
     
  15. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Wow! Much has happened while I was away. I will submit my reply without the benefit of thoroughly digesting the new posts (which I will do later - I need broadband).
    -----------

    Hi, Laaz. I should have looked to Morton's book for answers. It states that "Nucellar embryos are not uncommon in these hybrids and most of the cultivars are self-sterile, so a majority come true from seed".

    Jim,
    I'd be happy with whatever results from the seed and even happier if it's even a close facsimile of a Minneola. It's the journey that counts. I'm trying to reconcile statements such as Morton's and your observations. This neophytes's head will need some time to sort things out. I think much of my confusion lies with the definition of 'true to type' which you gave in summing up your reply: "Guaranteed true to type means the fruit from the seedlings will be a Tangelo". Then again, aren't nucellar seeds supposed to be genetically identical to the parent?

    Re: Florida Honey mandarin...could it have been pollinated by another nearby Trifoliate Orange rather than a case of the rootstock imposing its genetics on the scion? (Perhaps a newbie question here.)

    Your replies always lead to much thought. Given the choice I would of course always choose the grafted specimen to avoid all uncertainties that come with seed. However the discussions around seeds are always interesting.

    According to The Citrus Industry - Vol. 1, "It has recently been established (Cooper, Reece and Furr, 1962) that the Bowen variety used in some of the early citrus breeding work in Florida was in reality Duncan".

    ---
    By the information received to date from here and various other sources, it appears I'll have to pollinate using a Q-tip when this tree flowers; it's not going to have the benefit of bees as it's indoors all the time. This will be most interesting. I'll have to report back on all this when it takes place.
     
  16. AnotherAlterEgo

    AnotherAlterEgo Active Member

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    This discussion, even as it has been moved to a new thread, is quite fascinating. I hope to be able to employ the information that I have learned here in future endeavors. That said, I asked a question in the previous thread which I cannot find the answer for, so I'll try again. Millet, I assume you are the expert in this area, based on your expertly-written replies in this thread, so I'll redirect this question to you. Question: Is giberrelic acid useful in increasing yield on trees in the autonomic parthenocarpy category?
     
  17. Millet

    Millet Well-Known Member 10 Years

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    Junglekeeper, on what page of "The Citrus Industry" volme-1 did you see the information that Bowen Grapefruit is actually the same variety as Duncan? Quite a few fruits came from this same cross (Bowen?Duncan x Dancy)...Minneola, Lake, Orlando and Seminole. I did read that the Bowen grapefruit, was only a local variety grown the 1890's by a Mr. Frank Savage at Eustis, Florida, but was never distributed (page-646. The Citrus Industry V-1) - Jim, thank you for your thread, very informative. Let me digest it, before I ask additional questions. Thank you both. - Millet
     
  18. mr.shep

    mr.shep Well-Known Member 10 Years

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    I will be away for most of today.

    A Bordeaux mixture was applied to some
    Citrus to help in fruit set years ago. Think
    of one of the components of the old Bordeaux
    spray that was used quite a bit on Wine Grapes
    and you guys may have part of your answers
    for how we did things. I've been around Orlando
    Tangelos since 1969 and the Minneolas
    were not far behind in production plantings
    here but which Minneola did we plant and
    did we use more than one form at planting
    time?

    Who out here had the ability to cross a
    Minneola Tangelo onto let's say a Satsuma
    Mandarin then backcross back to a Minneola
    and still have the offspring called Minneola
    for select commercial plantings? Another
    question for you guys to think on, is the
    Honeybell the same form as the old
    Minneola that came to UC Riverside in
    1961? Our Navel Oranges that my
    parents planted did not come from a
    nursery, they came from an experimental
    station and they were cutting grown..

    I've got some backtrack homework to do
    myself later as there is one thing about the
    old Minneola that I need to double check.

    Jim
     
  19. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    The quote from TCI is in Chapter 4 - Horticultural Varieties of Citrus, section Pummelos and Grapefruits, subsection Grapefruit. My PDF copy of the digitized book does not have the original page numbers. Strangely, I cannot find the reference you noted on Bowen. I wonder if we're looking at different editions. The one I have has been updated since it makes references to "original volumes" of the book in its preface dated 1967.
     
  20. Millet

    Millet Well-Known Member 10 Years

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    Jim, I see that the Minneola growers in your area, have taken what is usually considered a negitive and turned it into a positive. The negitive being the poorer Minneola X Minneola cross pollination, and using that to set fewer, thus larger, fruit on their trees. Actually this type of cross pollination also eliminates the need for chemical or hand thinning of the fruit. As the market in your area must be for fresh out of hand fruit, then the lower number of fruit that sets, the larger each fruit will be at maturity. I would also think that each fruit would have a higher soluble solids content, due to the extra leaf photosynthates (sugars) per fruit. I re-learned something from you here, and that is once again, there is more that one right way to do things. Thanks. - Millet
     
  21. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Jim,
    How seedy is the fruit when Minneola is grown in a solid block? There must be a mix of fruit resulting from pollination (seeded) and from parthenocarpy (non-seeded). The ratio of seeded vs. non-seeded will give us an idea of how the fruit came about. Do you have a ballpark figure or a gut feel?

    Millet,
    Were you able to figure out the reason for the discrepancy in The Citrus Industry?

    As an aside, there were some organically grown Minneolas at the market that were small, didn't have the typical red-orange color, and many of which didn't have the characteristic neck. They looked more like ordinary Japanese mandarins. It's interesting how cultural differences can result in fruit that look so different.
     
  22. Millet

    Millet Well-Known Member 10 Years

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    Junglekeeper, yes I do know the reason for the discrepancy. I have all four volumes of "The Citrus Industry". Two of my books, volume-1 and volume-2 are the "original volumes" (First Edition) dated 1943. I was able to purchase them from Colgate University. I highly prize them. Take care. - Millet
     
  23. Millet

    Millet Well-Known Member 10 Years

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    AAE you ask: Question: Is giberrelic acid useful in increasing yield on trees in the autonomic parthenocarpy category? Your question has already been answered by Mr. Shep, five threads above. If you read his thread carefully you will see an answer to your question. However, I would add that, of course, giberelic acid is not required on autonomic parthenocarpic fruit in order for this type of citrus to set fruit. Some research HAS been carried out concerning the use of giberrelic on autonomic parthenocarpy fruit. It was found that giberelic acid applications (10 ppm) did aid in the REDUCTION of post bloom fruit drop, thereby increasing the amount of fruit held on the tree. As you probably already know, there are several reason for fruitlets to drop after bloom. One of these is hormonal, and it is believed that giberelic acid aids in this area. (this one's for Jim) - Millet
     
  24. AnotherAlterEgo

    AnotherAlterEgo Active Member

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    Millet - Thanks for pointing out MrShep's post. Very informative. Also, I appreciate the insight into the reduced fruit drop/higher yield experiment. Interesting stuff. Thanks again. I hope all is well.
     

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